// ========================================================================
// Copyright (c) 2006-2009 Mort Bay Consulting Pty. Ltd.
// ------------------------------------------------------------------------
// All rights reserved. This program and the accompanying materials
// are made available under the terms of the Eclipse Public License v1.0
// and Apache License v2.0 which accompanies this distribution.
// The Eclipse Public License is available at 
// http://www.eclipse.org/legal/epl-v10.html
// The Apache License v2.0 is available at
// http://www.opensource.org/licenses/apache2.0.php
// You may elect to redistribute this code under either of these licenses. 
// ========================================================================

package org.eclipse.jetty.util;

/* ------------------------------------------------------------ */
/**
 * UTF-8 StringBuilder. This class wraps a standard {@link java.lang.StringBuffer} and provides methods to append UTF-8 encoded bytes, that are converted into characters. This class is stateful and up to 6 calls to {@link #append(byte)} may be needed before state a character is appended to the string buffer. The UTF-8 decoding is done by this class and no additional buffers or Readers are used. The UTF-8 code was inspired by http://javolution.org
 */
public class Utf8StringBuilder extends Utf8Appendable
{

	final StringBuilder _buffer;

	public Utf8StringBuilder()
	{
		super(new StringBuilder());
		_buffer = (StringBuilder)_appendable;
	}

	public Utf8StringBuilder(int capacity)
	{
		super(new StringBuilder(capacity));
		_buffer = (StringBuilder)_appendable;
	}

	@Override
	public int length()
	{
		return _buffer.length();
	}

	public void reset()
	{
		_buffer.setLength(0);
		_more = 0;
		_bits = 0;
	}

	public StringBuilder getStringBuilder()
	{
		if (_more != 0)
			throw new NotUtf8Exception();
		return _buffer;
	}

	@Override
	public String toString()
	{
		if (_more != 0)
			throw new NotUtf8Exception();
		return _buffer.toString();
	}
}
